关键词: 离子注入, 离子束, 金属污染, 法拉第杯

Abstract: In response to the metal contamination problem faced by the semiconductor industry, the VIISta HCS ion implantation machine has several mature improvement measures. However, with the increasingly stringent metal purity requirements of the ion implantation process in advanced processes, it is urgent to identify other potential causes of metal contamination in this model. During the process of ion beam optimization and detection of this model, the equipment makes adjustments to airflow, voltage, current, and other hardware parameters. These adjustments may have an impact on the metal precipitation of the machine, leading to contamination. After verification, it is found that there is an increase in the metal aluminum content in the injected silicon wafer after checking the ion beam parameters. Theoretical analysis and experimental verification are conducted to address the issue of increased aluminum content. The results indicate that by manually moving the graphical Faraday cup multiple times, the early precipitation of aluminum element can be effectively promoted. By using specific program shields to perform ion beam channel cleaning operations, a 34% improvement in aluminum cleanliness is successfully achieved. This improvement significantly alleviates the problem of aluminum content deterioration during ion beam parameter inspection and improves process stability.

Key words: ion implantation, ion beam, metal contamination, Faraday cup